Fix navigation bar icons color when toggling dark mode on OMR1

Explicitly set navigation bar icon colors for the dark mode settings
fragment to work around issue on OMR1.

Bug: 942551
Change-Id: I165119f92b78dd59167e480987754fb74ff1d5b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1549923
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#647091}

chrome/android/java/src/org/chromium/chrome/browser/preferences/themes/ThemePreferences.java

@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.preferences.themes;
 
 import static org.chromium.chrome.browser.preferences.ChromePreferenceManager.UI_THEME_SETTING_KEY;
 
+import android.os.Build;
 import android.os.Bundle;
 import android.preference.PreferenceFragment;
 import android.support.annotation.IntDef;
@@ -15,6 +16,7 @@ import android.widget.ListView;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.chrome.browser.preferences.PreferenceUtils;
+import org.chromium.ui.UiUtils;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -54,6 +56,15 @@ public class ThemePreferences extends PreferenceFragment {
     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
+
+        // On O_MR1, the flag View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR in this fragment is not
+        // updated to the attribute android:windowLightNavigationBar set in preference theme, so
+        // we set the flag explicitly to workaround the issue. See https://crbug.com/942551.
+        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.O_MR1) {
+            UiUtils.setNavigationBarIconColor(getActivity().getWindow().getDecorView(),
+                    getResources().getBoolean(R.bool.window_light_navigation_bar));
+        }
+
         ListView listView = getView().findViewById(android.R.id.list);
         listView.setDivider(null);
     }

chrome/android/java/src/org/chromium/chrome/browser/ui/system/NavigationBarColorController.java

@@ -163,7 +163,7 @@ class NavigationBarColorController implements VrModeObserver {
         // The platform ignores the light navigation bar system UI flag when launching an Activity
         // in VR mode, so we need to restore it when VR is exited.
         // TODO(https://crbug.com/937946): How does this interact with immersive mode?
-        updateSystemUiVisibility(mUseLightNavigation);
+        UiUtils.setNavigationBarIconColor(mRootView, mUseLightNavigation);
     }
 
     @Override
@@ -195,7 +195,7 @@ class NavigationBarColorController implements VrModeObserver {
 
         setNavigationBarColor(useLightNavigation);
 
-        updateSystemUiVisibility(useLightNavigation);
+        UiUtils.setNavigationBarIconColor(mRootView, useLightNavigation);
     }
 
     @SuppressLint("NewApi")
@@ -207,14 +207,4 @@ class NavigationBarColorController implements VrModeObserver {
                             : Color.BLACK);
         }
     }
-
-    private void updateSystemUiVisibility(boolean useLightNavigation) {
-        int visibility = mRootView.getSystemUiVisibility();
-        if (useLightNavigation) {
-            visibility |= View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
-        } else {
-            visibility &= ~View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
-        }
-        mRootView.setSystemUiVisibility(visibility);
-    }
 }

ui/android/java/src/org/chromium/ui/UiUtils.java

@@ -490,4 +490,22 @@ public class UiUtils {
         }
         return sSystemUiThemingDisabled;
     }
+
+    /**
+     * Sets the navigation bar icons to dark or light. Note that this is only valid for Android
+     * O_MR1+.
+     * @param rootView The root view used to request updates to the system UI theme.
+     * @param useDarkIcons Whether the navigation bar icons should be dark.
+     */
+    public static void setNavigationBarIconColor(View rootView, boolean useDarkIcons) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O_MR1) return;
+
+        int systemUiVisibility = rootView.getSystemUiVisibility();
+        if (useDarkIcons) {
+            systemUiVisibility |= View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
+        } else {
+            systemUiVisibility &= ~View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
+        }
+        rootView.setSystemUiVisibility(systemUiVisibility);
+    }
 }